[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

US20060098137A1 - Polarizer, optical film using it, image display unit using them - Google Patents

Polarizer, optical film using it, image display unit using them Download PDF

Info

Publication number
US20060098137A1
US20060098137A1 US10/522,187 US52218705A US2006098137A1 US 20060098137 A1 US20060098137 A1 US 20060098137A1 US 52218705 A US52218705 A US 52218705A US 2006098137 A1 US2006098137 A1 US 2006098137A1
Authority
US
United States
Prior art keywords
polarizer
liquid crystal
film
retardation
polarizing plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/522,187
Other languages
English (en)
Inventor
Tadayuki Kameyama
Hiroaki Mizushima
Youichirou Sugino
Morimasa Wada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nitto Denko Corp
Original Assignee
Nitto Denko Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nitto Denko Corp filed Critical Nitto Denko Corp
Assigned to NITTO DENKO CORPORATION reassignment NITTO DENKO CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KAMEYAMA, TADAYUKI, MIZUSHIMA, HIROAKI, SUGINO, YOUICHIROU, WADA, MORIMASA
Publication of US20060098137A1 publication Critical patent/US20060098137A1/en
Priority to US12/230,372 priority Critical patent/US8698981B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H10K50/86—Arrangements for improving contrast, e.g. preventing reflection of ambient light

Definitions

  • the present invention relates to a polarizer, an optical film such as a polarizing plate using the same, and an image display device.
  • Liquid crystal displays have been used for desktop electronic calculators, electronic clocks, personal computers, word processors, and meters of automobiles and other machines.
  • Such a liquid crystal display includes in general a polarizing plate for visualizing alignment changes of the liquid crystal, and the polarizing plate has a very large influence on the display characteristics of the liquid crystal display.
  • a polarizing plate typically for example, a polarizing plate made of a polarizer (polarizing film) of a polyvinyl alcohol-based film or the like by absorbing and aligning a dichroic material such as iodine and organic dye, whose surfaces are laminated with protective films of triacetylcellulose or the like.
  • JP H14(2002)-028939 A discloses a polarizing plate using a polyvinyl alcohol-based polymer film that can be stretched uniformly in a simple manner.
  • a polarizer of the present invention is characterized as a polarizer containing a dichroic material in a matrix, and the in-plane retardation is in a range of 950 to 1350 nm at a measurement wavelength providing no absorption.
  • a display irregularity (particularly, a display irregularity in a black display) can be cancelled sufficiently at a time of application to various image display devices, particularly, to a large-sized or high-contrast display device or a flat panel display.
  • FIG. 1 is a cross-sectional view showing one example of an optical film of the present invention.
  • FIG. 2 is a cross-sectional view showing another example of an optical film of the present invention.
  • FIG. 3 is a cross-sectional view showing an example of a liquid crystal panel of the present invention.
  • FIG. 4 is a cross-sectional view showing another example of a liquid crystal panel of the present invention.
  • FIG. 5 (A) is a cross-sectional view showing a further example of a liquid crystal panel of the present invention, while (B) and (C) are cross-sectional views showing parts of (A).
  • FIG. 6 is a cross-sectional view showing one example of a backlight in an Example of the present invention.
  • FIG. 7 is a cross-sectional view showing another example of a backlight in an Example of the present invention.
  • FIG. 8 is a cross-sectional view showing another example of a backlight in an Example of the present invention.
  • FIG. 9 (A) is a cross-sectional view showing another example of a backlight in an Example, and (B) is a partial and schematic view of (A).
  • the polarizer of the present invention is characterized as a polarizer containing a dichroic material in a matrix, and its in-plane retardation is in a range of 950 to 1350 nm at a measurement wavelength providing no absorption. It is preferable that the in-plane retardation is set in a range of 1050 to 1250 nm, more preferably, in a range of 1100 to 1200 nm.
  • the in-plane retardation ( ⁇ nd) is expressed by the formula below, where nx and ny denotes respectively refractive indices in X-axis and Y-axis directions in the polarizer.
  • the X-axis direction denotes an axial direction presenting a maximum refractive index within the plane of the polarizer
  • the Y-axis direction denotes an axial direction perpendicular to the X-axis within the plane
  • d denotes a thickness of the polarizer.
  • the in-plane retardation for example, when the size of the polarizer is set in a range of (8 to 800 cm) ⁇ (15 to 1500 cm) and the retardation is measured at 28 to 1,200,000 measurement points in total provided at a pitch of 1 to 20 mm longitudinally and transversely, preferably all the measurement values are within the above range. In a specific example, when the retardation is measured at 12276 measurement points in total with a pitch of 2 mm in a polarizer of 25 cm ⁇ 20 cm, all the measurement values are preferably within the range.
  • the measurement wavelength is not limited particularly as long as the polarizer of the present invention does not provide absorption, i.e., the dichroic material does not provide absorption.
  • it is 800 to 1500 ⁇ m, preferably, 840 to 1200 nm, and particularly preferably, 1000 nm.
  • a chromatic dispersion ⁇ Rx represented by the formula below must be taken into consideration.
  • the absorption edge is x a
  • the x must be larger than the x a .
  • a differential retardation fluctuation ( ⁇ ) of the in-plane retardation is in a range of ⁇ 5 nm/mm to 5 nm/mm.
  • the differential retardation fluctuation ( ⁇ ) is, more preferably, in a range of ⁇ 4 nm to 4 nm/mm, and particularly preferably, in a range of ⁇ 2.5 nm/mm to 2.5 nm/mm.
  • the distance between the measurement points is preferably 1 to 100 mm, or more preferably, 3 to 70 mm from an aspect of precisely calculating retardation fluctuations occurring locally.
  • a distance between a measurement position exhibiting the maximum value and a measurement position exhibiting the minimum value is, for example, not more than 10 mm (more than 0) or not less than 100 mm, and a difference between the maximum value and the minimum value (in-plane retardation variation) is less than 60 nm.
  • the distance is not more than 7 mm or not less than 120 mm and the in-plane retardation variation is less than 45 nm, more preferably, the distance is not more than 5 mm or not less than 150 mm and the in-plane retardation variation is less than 45 nm.
  • a further preferred distance is 100 mm or more, and a particularly preferred distance is 150 mm or more.
  • the upper limit of the distance is not limited, but it corresponds to a size of the film.
  • the polarizer of the present invention will be used, for example, to a polarizing plate and an optical film, and further it can be used for various image display devices such as liquid crystal displays. Therefore, it can be a polarizer that is cut out previously (so-called ‘chip-cut’) corresponding to a size or the like of liquid crystal cells.
  • the polarizer of the present invention can be manufactured, for example, by subjecting a polymer film to a swelling treatment, a dyeing treatment by using a dichroic material, a crosslinking treatment, a stretching treatment, a washing treatment or the like, as described below.
  • the present invention is characterized in that a selection of the in-plane retardation for the polarizer of the above-mentioned range, while persons skilled in the art can produce such a polarizer having the in-plane retardation, on the basis of common knowledge in the art at the time of the application.
  • polymer film a conventionally known film can be used without any particular limitations.
  • the examples include hydrophilic polymer films such as a polyvinyl alcohol (PVA)-based film, a partially-formalized PVA-based film, a polyethylene terephthalate (PET)-based film, a film based on ethylene-vinyl acetate copolymer, and partially-saponified films thereof.
  • PVA polyvinyl alcohol
  • PET polyethylene terephthalate
  • PET polyethylene terephthalate
  • a film based on ethylene-vinyl acetate copolymer e.g., polyene-alignment films of dehydrated PVA and dehydrochlorinated polyvinyl chloride, and a polyvinylene-based film that is stretch-aligned can be used as well.
  • the PVA-based film is preferred, as it has an excellent dye-affinity provided by iodine as a dichroic material.
  • a length in a stretching direction for a polymer film is regarded as ‘length’ and a length perpendicular to the stretching direction is regarded as ‘width’.
  • the PVA film has a polymerization degree of, for example, ranging from 1700 to 4500, more preferably from 2400 to 4000, and the saponification degree is preferably in a range of 18 to 50%, and more preferably, in a range of 23 to 47%. It is also preferable that the glycerol content of the film is in a range of 7 to 20 wt % for example, more preferably, in a range of 8 to 18 wt %.
  • the thickness of the polymer film is, for example, in a range of 65 to 80 ⁇ m, more preferably, 70 to 85 ⁇ m.
  • the polymer film has a local thickness fluctuation of not more than 0.7 ⁇ m with respect to an average thickness, more preferably, not more than 0.5 ⁇ m/cm, and particularly preferably, not more than 0.2 ⁇ m/cm. Even when the thickness fluctuation of the polymer film exceeds 0.7 ⁇ m/cm, influences of the thickness fluctuation can be avoided by, for example, optimizing the conditions of below-mentioned treatments such as swelling, crosslinkng and stretching, or by controlling the drainage.
  • a local thickness fluctuation is not more than 0.7 ⁇ m/cm with respect to an average thickness
  • a thickness fluctuation between two points separated from each other by 1 to 100 mm i.e., ‘(difference in thickness between the two points)/(distance between the two points)’ is not more than 0.7 ⁇ m/cm.
  • the average thickness for example, a PVA-based film having a maximum width of 2600 mm can be measured at 2600 points.
  • the present invention is not restricted thereto.
  • the polymer film it is preferable, for example, to use a film that has less swelling variation in the next step of swelling treatment, i.e., a film that has less thickness variation caused by the swelling. Thereby, variations in retardation, content of the dichroic material and transmittance can be decreased further for the thus produced polarizer.
  • a polymer film having less irregularities in the crystallization degree and thickness, and less variation in the water content A polymer film with substantially no variation in the glycerol content is preferred as well.
  • the polymer film (untreated film) is impregnated to swell in a swelling bath and also stretched in the swelling bath.
  • the swelling bath for example, water, an aqueous solution of glycerol, an aqueous solution of potassium iodide or the like, can be used.
  • the swelling treatment can be carried out as in a conventional technique without any particular limitations for the conditions, for example, the impregnation can be carried out for 60 seconds to 300 seconds (preferably, 90 to 240 seconds, and more preferably, 120 to 180 seconds) in a swelling bath of 20 to 30° C.
  • the swelling time is 60 seconds or more, for example, since contamination of a dyebath in the following dyeing step can be avoided sufficiently, problems in the long-run can be reduced, and the dyeing irregularity can be prevented sufficiently.
  • the swelling time is not more than 300 seconds, ruptures which may occur at the time of stretching in a subsequent stretching step can be suppressed sufficiently.
  • the polymer film is swelled in general 1.1 to 1.5 times the length of the untreated film. It is further preferable that the film is stretched to swell further to 1 to 1.3 times (preferably, 1.05 to 1.25 times) the length of the swelled film.
  • a roll such as an expander roll, a spiral roll, and a crown roll in the swelling bath, for example.
  • a roll for removing wrinkles in the center of the untreated film.
  • the polymer film has less variation in the swelling.
  • the thickness variation after the swelling is preferred to be 8% or less, more preferably, 5% or less, and particularly preferably, 2.5% or less.
  • the film will be stretched more by the swelling, while the film will not be stretched so much when the thickness is increased. In this manner, since a thin part of the film will be swelled more in the film, the film is preferably swelled gradually for saturation.
  • a difference between a maximum value and a minimum value of the thickness is in the relationship below with a distance between a position exhibiting the maximum value and a position exhibiting the minimum value. That is, ‘(difference between maximum value and minimum value)/(distance)’ is not more than 1.5 ⁇ m for example, preferably not more than 1.0 ⁇ m/cm, more preferably, not more than 0.5 ⁇ m/cm. It is particularly preferable that the distance is not more than 5 mm or not less than 250 mm, more preferably, not more than 10 mm or not less than 150 mm, and particularly preferably, not more than 20 mm or not less than 100 mm.
  • a slight stretch at a position exhibiting a minimum thickness in a direction (TD direction) perpendicular to the stretching direction, which is caused by shrinkage at the position exhibiting the maximum thickness can be prevented sufficiently.
  • the distance is not more than 10 mm, dyeing irregularity can be inconspicuous further because of the short distance.
  • stretching at the position having the maximum value and the position having the minimum value can be carried out slowly, which can serve to prevent sufficiently the above-mentioned stretching in the perpendicular direction accompanying the shrinkage.
  • the polymer film is pulled out of the swelling bath, impregnated, for example, in a dyebath containing a dichroic material, and further stretched uniaxially in the dyebath. That is, the polymer film is impregnated for adsorbing the dichroic material and the stretching carried out for aligning the dichroic material in one direction.
  • any of well-known materials can be used for the well-known dichroic material.
  • the examples include iodine and organic dyestuffs.
  • the organic dyestuff can be used preferably in a state combined with at least one of other dyestuffs for neutralization of the visible ray region.
  • the solution for the dyebath can be a solution prepared by dissolving the dichroic material in a solvent.
  • a solvent for example, water can be used for the solvent, and an organic solvent compatible with water can be included further.
  • concentration of the dichroic material in the solution is not limited particularly, preferably it ranges from 0.005 to 10 wt %, and preferably from 0.01 to 0.08 wt %.
  • the time of impregnation of the polymer film in the dyebath is not limited particularly, for example, it ranges from 30 to 120 seconds, preferably from 40 to 110 seconds, and more preferably from 50 to 100 seconds.
  • the temperature for the dyebath is typically from 10 to 35° C.
  • the stretch rate in the dyeing treatment is, for example, preferably in a range of 2 to 3.2 times with respect to the length of the polymer film before swelling (untreated film), more preferably, from 2.2 to 3.1 times, and particularly preferably, from 2.4 to 3.0 times.
  • the stretch rate is 2 or more, for example, waving in the stretching direction (MD direction) of the film can be suppressed sufficiently, and thus the problem of a dye irregularity can be prevented.
  • the rate is 3.2 or less, a sufficient polarization degree can be maintained.
  • any of the above-mentioned various rolls can be arranged in the dyebath, thereby removing the wrinkles in the polymer film.
  • the wrinkles can be removed by the rolls before or after impregnating the polymer film in the dyebath.
  • the polymer film is pulled out from the dyebath, impregnated in a crosslinking bath containing a crosslinking agent, and further stretched in the crosslinking bath.
  • the crosslinking treatment is performed to retain the running stability.
  • the crosslinking agent can be selected from known materials like boron compounds such as boric acid and borax, glyoxal, and glutaraldehyde. These materials can be used alone or can be combined with at least any one of the remaining materials.
  • the solution for the crosslinking bath can be a solution prepared by dissolving the crosslinking agent in a solvent.
  • the solvent can be water, and it can further contain an organic solvent compatible with water.
  • the concentration of the crosslinking agent in the solution is not limited particularly, preferably, it ranges from 1 to 10 wt %, more preferably from 1.5 to 8 wt %.
  • the crosslinking agent is boric acid, for example, the range is 1.5 to 7 wt %, preferably 2 to 6 wt %.
  • the aqueous solution can contain an auxiliary of iodide such as potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide, in addition to the boric acid compound.
  • the content of the auxiliary in the solution is, for example, from 1 to 18 wt %, preferably from 2 to 18 wt %.
  • the auxiliary is potassium iodide
  • the range is 2 to 15 wt %, preferably, 5 to 14 wt %.
  • a combination of boric acid and potassium iodide is particularly preferred.
  • a typical range for a ratio (weight ratio) of the boric acid to the potassium iodide in the solution is, for example, from 7:1 to 1:9, preferably, from 5:1 to 1:5.
  • the temperature for the dyeing treatment and the temperature for the crosslinking treatment are in a relationship of ‘(dyeing temperature) ⁇ (crosslinking temperature) ⁇ (stretching temperature)’. Specifically, a range from 8 to 75° C. is preferred, and a more preferable range is 20 to 70° C.
  • the time for impregnating the polymer film is not limited particularly, it generally ranges from 25 to 150 seconds, preferably from 30 to 120 seconds.
  • the stretch rate in this crosslinking treatment is, for example, not more than 3.5 times, or preferably, not more than 3.3 times the length of the untreated film.
  • the polymer film is pulled out from the crosslinking bath, impregnated in a final stretching bath, and further stretched in this stretching bath.
  • the crosslinking treatment and the stretching treatment can be repeated further.
  • the solution for the stretching bath is not limited particularly, it is selected, for example, from solutions containing boric acid, potassium iodide, various metal salts and other iodides, and zinc compounds.
  • the solvent can be, water, ethanol, or the like.
  • the concentration ranges typically from 2 to 10 wt %, preferably from 3 to 6 wt %. It is preferable that the boric acid concentration in the stretching bath is higher than the boric acid concentration in the crosslinkng bath. It is also preferable to further use potassium iodide, and in such a case for example, it is preferable that the concentration is set higher than the concentration of the potassium iodide in the above-mentioned crosslinking bath. The concentration of the potassium iodide ranges typically from 4 to 10 wt %, and preferably from 6 to 8 wt %. It is preferable, for example, that the concentration of the potassium iodide in the stretching bath is set higher than the concentration of the potassium iodide in the above-mentioned crosslinking bath.
  • a typical range of the temperature of the stretching bath is from 40 to 75° C., preferably from 50 to 70° C.
  • the stretch rate in the stretching treatment ranges, for example, from 5.5 to 6.5 times, preferably from 5.8 to 6.4 times, and more preferably from 6.0 to 6.2 times the length of the untreated film.
  • a range of 35 seconds to 60 seconds is preferable, and more preferable range is from 40 seconds to 50 seconds.
  • the polymer film is pulled out of the stretching bath, impregnated in an iodide-containing solution, washed with water, and dried.
  • the above-described iodides can be used for the iodide-containing solution. Potassium iodide and sodium iodide or the like are especially preferred.
  • the solvent can be water. Residue of the boric acid used in the stretching treatment can be washed out from the polymer film by using the iodide-containing solution.
  • the concentration ranges, for example, from 0.5 to 20 wt %, preferably from 1 to 15 wt %, and particularly preferably from 1.5 to 7 wt %. It is preferable that the temperature of the aqueous solution ranges from 15 to 40° C., more preferably from 20 to 35° C.
  • the time for impregnating in the aqueous solution is typically 2 to 15 seconds, preferably 3 to 12 seconds. There is no particular limitation on the number of cycles for washing in water after the impregnation in the iodide-containing aqueous solution.
  • the thus stretched polymer film is deformed so that the width and the thickness satisfy the conditions below.
  • the neutralization of the thus produced polarizer of the present invention will be improved further.
  • the polarizer of the present invention and a polarizing plate using the same are arranged in parallel Nicols, yellowish coloring can be suppressed further.
  • bluish or reddish coloring can be suppressed further.
  • the stretched polymer film is deformed to have a width ranging from (1/ ⁇ square root over (a) ⁇ 100)% to (1/ ⁇ square root over (a) ⁇ 125)% when the polymer film before swelling (untreated film) has a width of 100%, preferably from (1/ ⁇ square root over (a) ⁇ 100)% to (1/ ⁇ square root over (a) ⁇ 120)%, and more preferably from (1/ ⁇ square root over (a) ⁇ 100)% to (1/ ⁇ square root over (a) ⁇ 110)%.
  • a preferable range is 41 to 51%, and more preferably 41 to 45%.
  • the width of the polymer film denotes a length perpendicular to the stretch direction (longitudinal direction) as mentioned above.
  • the thickness may be irregular.
  • the stretched polymer film is deformed so that a thickness at the thinnest part will range from (1/ ⁇ square root over (a) ⁇ 80)% to (1/ ⁇ square root over (a) ⁇ 100)%, preferably from (1/ ⁇ square root over (a) ⁇ 85)% to (1/ ⁇ square root over (a) ⁇ 100)%, and more preferably from (1/ ⁇ square root over (a) ⁇ 90)% to (1/ ⁇ square root over (a) ⁇ 100)% when the thickness of the untreated film is 100%, because it is preferable that ⁇ n and further the thickness d are increased due to the high stretch rate.
  • the thinnest part of the film tends to become thinner due to shrinkage in the width direction of the periphery and the other parts, and thus the uniaxiality may deteriorate and the optical characteristics will be degraded locally, which may cause a considerable irregularity.
  • the stretched polymer film it is preferable for the stretched polymer film that the width and the thickness satisfy the relationship expressed below. That is, a value expressed by the Formula (I) below is, for example, in a range of 0.9 to 1.1, or preferably in a range of 0.95 to 1.05. (T b ⁇ W b )/(T a ⁇ W a ) (I)
  • T a average thickness of stretched polymer film
  • T b average thickness of unstretched polymer film (untreated film)
  • W b width of unstretched polymer film (untreated film)
  • the polarizer of the present invention which contains a dichroic material in a matrix
  • the drying is carried out, for example, by natural dry, air dry, heat dry or the like, without any particular limitations.
  • the temperature is typically 20 to 40° C., and preferably 22 to 35° C.
  • the treatment time is typically 0.5 to 5 minutes, preferably 1 to 4 minutes, and more preferably, 1.5 to 3 minutes.
  • the thickness of the finally-obtained polarizer of the present invention is preferably in a range of 5 to 40 ⁇ m, more preferably 15 to 35 ⁇ m, and particularly preferably 17 to 32 ⁇ m.
  • the thickness of 5 ⁇ m or more serves to, for example, improve further the mechanical strength.
  • the thickness of 40 ⁇ m or less will serve to improve further the optical characteristics, for example, the thickness can be reduced easily at the time of applying the film to a flat panel.
  • the polarizers are not limited to the ones mentioned above, but similar polarizers can be formed, for example, by mixing a dichroic material in PET or the like for forming a film to be stretched.
  • a polarizer can be formed by stretch-aligning a polyvinylene-based film or by further kneading a dichroic material in the film.
  • Alternative examples include an O-type polarizer (U.S. Pat. No.
  • an optical film of the present invention includes the polarizer of the present invention. Examples of the optical film are described below.
  • a first example of the optical film of the present invention is a polarizing plate that, for example, includes the polarizer of the present invention and a transparent protective layer, where the transparent protective layer is arranged on at least one surface of the polarizer.
  • the transparent protective layer can be arranged on one of or both surfaces of the polarizer. When laminating on both the surfaces, the transparent protective layers can be the same type or different from each other.
  • the measurement can be carried out in a state, for example, that the transparent protective layer is removed by using a solvent or the like from the polarizing plate of the present invention.
  • the retardation of the transparent protective layer is minor (substantially 0 nm)
  • the polarizing plate with the transparent protective layer can be measured.
  • the water content is preferably 2 to 5%, more preferably 2.5 to 4.5%, and particularly preferably 3 to 4%.
  • FIG. 1 shows a cross-sectional view of one example of the polarizing plate.
  • a polarizing plate 10 includes a polarizer 1 and two transparent protective layers 2 , where the transparent protective layers 2 are arranged respectively on both surfaces of the polarizer 1 .
  • the transparent protective layers 2 can be selected from conventionally known transparent protective films without any particular limitations. Preferably, they are polymer films excellent in some characteristics such as transparency, mechanical strength, thermal stability, moisture shielding property, and isotropism. Specific examples of materials for the transparent protective layers include cellulose-based resins such as triacetylcellulose, and transparent resins based on e.g., polyester, polycarbonate, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, acrylic, acetate, and polyolefin.
  • cellulose-based resins such as triacetylcellulose
  • Resins that will be cured by heat or ultraviolet rays which are based on e.g., the above-mentioned acrylic, urethane, acrylic urethane, epoxy, and silicone, can be used as well. Materials having lower photoelastic coefficient, such as polynorbornene-based resin, are preferable as well.
  • a film or the like made by extruding a mixture of an alternating copolymer of isobutene and N-methyl maleimide and a acrylonitrile-styrene copolymer as described in JP 2001-343529 (WO 01/37007) and JP 2002-328233 A, can be used as well.
  • Such a film can be provided, for example, as described below.
  • the alternating copolymer (100 weight parts) containing 50 mol % of N-methyl maleimide and the copolymer (67 weight parts) containing 27 wt % of acrylonitrile and 73 wt % of styrene are melt-kneaded, and the thus obtained pellet is fed to a melt-extruder having a T-die so as to produce a film of an untreated film.
  • This film is subjected to a free-end vertical-uniaxial stretch under a condition of a stretch speed of 100 cm/min., stretch rate of 1.45, and a stretch temperature of 162° C.
  • these transparent protective films can have surfaces saponified by using alkali or the like.
  • a TAC film is preferred from an aspect of the polarization characteristics, the durability or the like, and a TAC film with a saponified surface is more preferable.
  • the transparent protective layers are colorless, for example.
  • a retardation value (Rth) of the film in the thickness direction as represented by the following equation is in a range of ⁇ 90 nm to +75 nm. More preferably, it is from ⁇ 80 nm to +60 nm, and particularly preferably from ⁇ 70 nm to +45 nm.
  • the retardation value is within the range of ⁇ 90 nm to +75 nm, coloring (optical coloring) of the polarizing plate, which is caused by the protective film, can be solved sufficiently.
  • Rth [ ⁇ ( nx+ny )/2 ⁇ nz] ⁇ d
  • nx, ny and nz respectively denote refractive indices of X-axis, Y-axis and Z-axis in the transparent protective layer.
  • the X-axis denotes an axial direction presenting a maximum refractive index within the transparent protective layer
  • the Y-axis denotes an axial direction perpendicular to the X-axis within the plane
  • the Z-axis denotes a thickness direction perpendicular to the X-axis and the Y-axis.
  • the thickness of the transparent protective layer is not limited particularly, preferably it is not more than 500 ⁇ m for example, for the purpose of reducing thickness of the polarizing plate, preferably, ranging from 1 to 300 ⁇ m, and more preferably, from 5 to 300 ⁇ m.
  • the transparent protective layer can be treated to provide characteristics such as hard coating, antireflection, anti-sticking, diffusion and anti-glaring.
  • Hard coating treatment is applied, for example, to prevent scratches on the surfaces of the polarizing plate.
  • a surface of the transparent protective layer is applied with a coating film of a cured resin with excellent hardness and smoothness.
  • the cured resin can be selected from ultraviolet cured resins of silicone base, urethane base, acrylic base, and epoxy base. The treatment can be carried out in a conventionally known method.
  • Antireflection treatment may be applied to prevent reflection of external light on the surface of the polarizing plate, and carried out by forming such an anti-reflection film or the like in a conventionally known method. Anti-sticking treatment is carried out for prevention of sticking with adjacent layers.
  • the anti-glare treatment aims at preventing such inhibition of visibility.
  • the anti-glare treatment can be carried out, for example, by providing microscopic asperities on a surface of the transparent protective layer by a conventionally known method. Such microscopic asperities can be provided, for example, by roughening the surface by sand-blasting or embossing, or by blending transparent fine particles in the above-described transparent resin when forming the transparent protective layer.
  • the above-described transparent fine particles will be selected from, for example, silica, alumina, titania, zirconia, stannic oxide, indium oxide, cadmium oxide, antimony oxide and the solid solutions.
  • the average diameter of the transparent fine particles is, for example, from 0.5 ⁇ m to 50 ⁇ m, through there is no particular limitation.
  • Inorganic fine particles having electroconductivity can be used as well.
  • the particles can be organic fine particles comprising, for example, crosslinked or uncrosslinked polymer particles.
  • An amount of the transparent fine particles is from 2 weight parts to 50 weight parts, and generally, from 5 weight parts to 25 weight parts, for 100 weight parts of a transparent resin, though there is no particular limitation.
  • An anti-glare layer comprising the transparent fine particles can be provided, for example, as the transparent protective layer.
  • the anti-glare layer can function as a diffusion layer to diffuse light transmitted through the polarizing plate in order to enlarge viewing angles.
  • the above-mentioned layers such as the antireflection layer, the diffusion layer and the anti-glare layer can be laminated on the polarizing plate, as a sheet of optical layers comprising these layers, separately from the transparent protective layer.
  • the above-described polarizer can be adhered to the transparent protective layer in a conventionally known method without any particular limitations.
  • adhesives including pressure-sensitive adhesives can be used, and the adhesive can be selected appropriately, e.g., depending on the kinds of the polarizing films and the transparent protective layers.
  • the adhesive or the pressure-sensitive adhesive can be based on PVA, modified PVA, and urethane-based polymer.
  • the adhesive or the like can contain a water-soluble crosslinking agent such as boric acid, borax, glutaraldehyde, melamine, oxalic acid, chitin, chitosan, metal salt, and an alcohol-based solvent, for crosslinking vinyl alcohol-based polymers.
  • a PVA-based adhesive is preferably used for a polarizer of a PVA-based film in view of its adhesion stability.
  • the thickness of the adhesive layer is not limited particularly, for example, it ranges from 1 nm to 500 nm, preferably from 10 nm to 300 nm, and more preferably from 20 nm to 100 nm.
  • drying treatment is performed preferably in order to, for example, prevent peeling due to influences of humidity and heat and provide a polarizing plate being excellent in light transmittance and polarization degree.
  • the drying temperature can be determined suitably corresponding to the kinds of the adhesive or pressure-sensitive adhesive in use, without any particular limitations.
  • the adhesive is a water-soluble adhesive such as PVA-based, modified PVA-based, urethane-based or the like as mentioned above, for example, the preferred drying temperature ranges from 60 to 75° C., more preferably from 60 to 70° C.
  • the drying time is preferably about 1 to 10 minutes.
  • FIG. 2 is a cross-sectional view of a polarizing plate having such a pressure-sensitive adhesive layer.
  • a polarizing plate 20 includes the polarizing plate 10 as shown in FIG. 1 and also a pressure-sensitive adhesive layer 3 , and the pressure-sensitive adhesive layer 3 is arranged on the surface of one of the transparent protective layers 2 on the polarizing plate 10 .
  • the pressure-sensitive adhesive layer can be formed on the transparent protective layer by any methods, for example, a method of applying a solution or a melt of a pressure-sensitive adhesive directly onto a predetermined face of the transparent protective layer by expansion such as flow-expansion and coating so as to form a layer, or a method of forming the pressure-sensitive adhesive layer in a similar manner on a separator as mentioned below and transferring it onto a predetermined face of the transparent protective layer.
  • a pressure-sensitive adhesive layer can be formed on one of the surfaces of the polarizing plate as shown in FIG. 2 , it is not for limitation but pressure-sensitive adhesive layers can be arranged on both the surfaces as required.
  • the pressure-sensitive adhesive layers can be formed by suitably using conventionally known pressure-sensitive adhesives based on, for example, acrylic, silicone, polyester, polyurethane, polyether, and rubbers.
  • a pressure-sensitive adhesive with low moisture absorption coefficient and excellent heat resistance is preferable particularly from aspects of prevention of foaming and peeling phenomena caused by moisture absorption, prevention of degradation of optical characteristics and warping of the liquid crystal cell caused by difference in the thermal expansion, and furthermore, formation of liquid crystal displays with high quality and excellent durability, and the like.
  • the pressure-sensitive adhesives include pressure-sensitive adhesives based on acrylic, silicone, acrylic silicone, polyester, and heat-resistant rubbers or the like.
  • a pressure-sensitive adhesive layer containing microparticles and exhibiting light-diffusion can be used.
  • the pressure-sensitive adhesive layer is covered with a separator by the time the pressure-sensitive adhesive layer is used so that contamination will be prevented.
  • the separator can be made of an appropriate thin sheet such as a transparent protective film by coating a peeling agent if required, and the peeling agent may be selected, for example, from a silicone-based agent, a long-chain alkyl-based agent, a fluorine-based agent, an agent comprising molybdenum sulfide or the like.
  • the thickness of the pressure-sensitive adhesive layer is 5 to 35 ⁇ m for example, more preferably 10 to 25 ⁇ m, and particularly preferably 15 to 25 ⁇ m.
  • the thickness is set within this range, for example, even if the size of the polarizing plate changes, stress caused by the dimensional change can be relieved.
  • the polarizing plate of the present invention can be used for forming a liquid crystal cell and a liquid crystal display or the like.
  • the polarizer can be cut (chip-cut) corresponding to the size of the liquid crystal cell or the like in a state being laminated with a transparent protective layer or the like.
  • the polarizer can be cut and then bonded with a transparent protective layer.
  • a second example of the optical film of the present invention is a laminate including either the polarizer of the present invention or the polarizing plate according to the first example, and also at least one of a polarization converter and a retardation film.
  • the polarization converter can be an element used for forming in general a liquid crystal display or the like, and the examples include an anisotropic reflective polarizer and an anisotropic light-scattering polarizer.
  • These polarization converters can be used as a single layer, or at least two layers can be laminated. When two or more layers are used, the layers can be the same type or different from each other.
  • the anisotropic reflective polarizer is preferably, for example, a composite of a cholesteric liquid crystal layer and a retardation plate, and the retardation plate exhibits retardation of 0.2 to 0.3 times, more preferably 0.25 times the wavelength included in a reflection band of the anisotropic reflective polarizer.
  • the cholesteric liquid crystal layer is an alignment film of a cholesteric liquid crystal polymer or a product including the alignment liquid crystal layer supported on a film base, which has a characteristic of reflecting either counterclockwise or clockwise circularly-polarized light while transmitting the other light.
  • the wavelength can be determined arbitrarily as long as it is within the reflection band of the anisotropic reflective polarizer.
  • the cholesteric liquid crystal layer can be, for example, a multilayer film of a dielectric or a multilayer laminate of thin films different from each other in the refractive anisotropy, which transmits linearly-polarized light of a predetermined polarization axis while reflecting the other light.
  • anisotropic reflective polarizer for example, DBEF series (trade name) or the like produced by 3M Co. can be used.
  • a reflective grid polarizer is preferred as well.
  • a specific example thereof is Micro Wires (trade name) or the like produced by Moxtek.
  • anisotropic light-scattering type polarizer for example, DRPF (trade name) or the like produced by 3M Co., can be used.
  • the polarizer of the present invention can be used for forming a liquid crystal display or the like, for example, a reflective plate, a semitransparent reflective plate, a retardation plate including a ⁇ plate or the like such as a half wavelength plate and a quarter wavelength plate, a viewing-angle compensation plate, and a brightness enhancement film as mentioned below.
  • These optical layers can be used alone or can be combined with at least one of the other optical layers.
  • a polarizing plate including such optical layers, particularly, a polarizing plate or the like including a laminate of a reflective polarizing plate, a semitransparent reflective polarizing plate, an elliptically-polarizing plate, a circularly-polarizing plate, a viewing-angle compensating film and a brightness enhancement film, is preferred.
  • the reflective polarizing plate includes further a reflector, for example, laminated on the polarizing plate of the first example as mentioned above.
  • the semitransparent reflective polarizing plate has further a semitransparent reflector laminated on the polarizing plate.
  • such a reflective polarizing plate is arranged on a backside of a liquid crystal cell in order to make a liquid crystal display (reflective liquid crystal display) to reflect incident light from a visible side (display side).
  • the reflective polarizing plate has some merits, for example, assembling of light sources such as backlight can be omitted, and thus the liquid crystal display can be thinned further.
  • the reflective polarizing plate can be formed in any conventionally known manner such as forming a reflector of metal or the like on one surface of the polarizing plate having the elastic modulus. Specifically for example, a transparent protective film of the polarizing plate is prepared by matting one surface (exposed surface) if required. On this surface, a foil comprising a reflective metal such as aluminum or a deposition film is applied to form a reflective polarizing plate.
  • An additional example of a reflective polarizing plate comprises the above-mentioned transparent protective film having a surface of a microscopic asperity due to contained fine particles, and also a reflector corresponding to the microscopic asperity.
  • the reflector having a microscopic asperity surface diffuses incident light by irregular reflection so that directivity and glare can be prevented and irregularity in color tones can be controlled.
  • This reflector can be formed by disposing a metal foil or a metal deposition film directly on a microscopic asperity surface of the transparent protective layer in any appropriate methods including deposition such as vacuum deposition, and plating such as ion plating and sputtering.
  • the reflector can be used as a reflective sheet formed by providing a reflective layer onto a proper film similar to the transparent protective film. Since a typical reflective layer of a reflector is made of a metal, it is preferable in use of the reflector that the reflecting surface of the reflective layer is coated with a film, a polarizing plate or the like in order to prevent the reflection rate from reduction due to oxidation. As a result, the initial reflection rate is maintained for a long period, and a separate protective layer can be omitted.
  • a semitransparent polarizing plate is provided by replacing the reflector in the above-mentioned reflective polarizing plate by a transflector, and it is exemplified by a half mirror that reflects and transmits light at the reflective layer.
  • such a semitransparent polarizing plate is arranged on a backside of a liquid crystal cell.
  • incident light from the visible side is reflected to display an image when the liquid crystal display is used in a relatively bright atmosphere, while in a relatively dark atmosphere, an image is displayed by using a built-in light source such as a backlight in the backside of the semitransparent polarizing plate.
  • the semitransparent polarizing plate can be used to form a liquid crystal display that can save energy for a light source such as a backlight under a bright atmosphere, while a built-in light source can be used under a relatively dark atmosphere.
  • the following explanation is about an elliptically-polarizing plate or a circularly-polarizing plate formed by laminating a retardation plate or ⁇ plate on a polarizing plate as in the above-mentioned first example.
  • the above-described elliptically-polarizing plate is effective in compensating (preventing) colors (for example, blue or yellow) generated due to birefringence in a liquid crystal layer of a super twist nematic (STN) liquid crystal display so as to provide a black-and-white display free of such colors.
  • An elliptically-polarizing plate with controlled three-dimensional refractive index is preferred further since it can compensate (prevent) colors that will be observed when looking at a screen of the liquid crystal display from an oblique direction.
  • the circularly-polarizing plate is effective in adjusting color tones of an image of a reflective liquid crystal display that has a color image display, and the polarizing plate serves to prevent reflection as well.
  • the retardation plate is used for modifying linearly-polarized light to either elliptically-polarized light or circularly-polarized light, modifying either elliptically-polarized light or circularly-polarized light to linearly-polarized light, or modifying a polarization direction of linearly-polarized light.
  • a retardation plate called a quarter wavelength plate ( ⁇ /4 plate) is used for modifying linearly-polarized light to either elliptically-polarized light or circularly-polarized light, and for modifying either elliptically-polarized light or circularly-polarized light to linearly-polarized light.
  • a half wavelength plate ( ⁇ /2 plate) is used in general for modifying a polarization direction of linearly-polarized light.
  • Examples of the retardation plates include birefringent films, alignment films of liquid crystal polymers, and laminates of alignment layers of liquid crystal polymers supported by the films.
  • the birefringent films can be prepared by stretching films of any suitable polymers such as polycarbonate, PVA, polystyrene, polymethyl methacrylate, polyolefins including polypropylene, polyallylate, polyamide, and polynorbornene.
  • the retardation plate can have a retardation suitable for intended uses such as compensation of a viewing angle (e.g., widening of viewing angle) and compensation of coloring caused by birefringence of the liquid crystal layer, or plates having varied wavelengths such as a half wavelength plate and a quarter wavelength plate.
  • the retardation plate can be an incline-alignment film having a refractive index controlled in the thickness direction.
  • Two or more kinds of retardation plates can be laminated for forming a laminate with controlled optical characteristics such as the retardation.
  • the incline-alignment film is produced, for example, by adhering a heat shrinkable film onto a polymer film and stretching and/or shrinking the polymer film under an influence of a shrinking force provided by the heat, or by aligning obliquely a liquid crystal polymer.
  • the polarizing plate described below comprises an additional viewing-angle compensating film laminated on the polarizing plate of the first example.
  • the viewing-angle compensating film is used for widening a viewing angle so that an image can be clear relatively when a screen of a liquid crystal display is seen not in a direction perpendicular to the screen but in a slightly oblique direction.
  • a viewing-angle compensating film can be a triacetylcellulose film coated with a discotic liquid crystal, or a retardation plate.
  • a retardation plate used for an viewing-angle compensating film is a two-way stretched film such as a birefringent polymer film stretched biaxially in the face direction and an incline-alignment polymer film with controlled birefringence in the thickness direction that is stretched uniaxially in the face direction and stretched also in the thickness direction.
  • the incline-alignment film is prepared by, for example, adhering a heat shrinkable film to a polymer film and stretching and/or shrinking the polymer film under an influence of a shrinkage force provided by heat, or by aligning obliquely a liquid crystal polymer.
  • a polymer as a material of the retardation plate is similar to the polymer used for the above-mentioned retardation plate.
  • a polarizing plate described below includes further a brightness enhancement film laminated on the polarizing plate of the first example.
  • this polarizing plate is arranged on a backside of a liquid crystal cell in use.
  • the brightness enhancement film reflects linearly-polarized light of a predetermined polarizing axis or circularly-polarized light in a predetermined direction while the same film transmits other light. It allows entrance of light from a light source such as a backlight so as to obtain transmitted light in a predetermined polarization state, while reflecting light other than light in the predetermined polarization state. Light that is reflected at this brightness enhancement film is reversed through a reflector or the like arranged additionally behind the brightness enhancement film.
  • the reversed light that re-enters the brightness enhancement film is transmitted partly or entirely as light in a predetermined polarization state, so that light transmitting the brightness enhancement film is increased and polarized light that is hardly absorbed in the polarizing film (polarizer) is supplied.
  • quantity of light available for the liquid crystal display etc. can be increased to enhance brightness.
  • the brightness enhancement film repeatedly prevents light having a polarization direction to be absorbed in the polarizer from entering the polarizer, and reflects the light on the brightness enhancement film, reverses the light through a reflective layer or the like arranged behind, and makes the light re-enter the brightness enhancement plate. Since the polarized light that is reflected and reversed between them is transmitted only if the light has a polarization direction to pass the polarizer, light from a backlight or the like can be used efficiently for displaying images of a liquid crystal display in order to provide a bright screen.
  • a diffusion plate can also be provided between the brightness enhancement film and a reflective layer such as the above-described reflector. Polarized light reflected by the brightness enhancement film is directed to the reflector.
  • the diffusion plate diffuses the passing light uniformly and at the same time, it cancels the polarization so as to provide a depolarized state. Namely, the diffusion plate converts the light back into its original state as natural light.
  • This depolarized light i.e., natural light is directed to the reflector, reflected at the reflector, and it passes again the diffusion plate so as to re-enter the brightness enhancement film.
  • the state of natural light is recovered by repeating this series of actions.
  • the diffusion plate serves to maintain brightness of the display screen and decrease irregularity in the brightness. That is, a display screen having uniform brightness can be obtained by providing a diffusion plate for recovering natural light, since the diffusion plate has a diffusion function and further it can increase appropriately the repeated reflection of the initial incident light.
  • the brightness enhancement film is advantageously selected from a multilayer thin film of a dielectric or a multilayer lamination of thin films with varied refraction aeolotropy that transmits linearly-polarized light having a predetermined polarization axis while reflecting other light.
  • a specific example that can be used for this is DBEF (trade name) or the like produced by 3M Co.
  • Alternative examples include a cholesteric liquid crystal layer, more specifically, an alignment film of a cholesteric liquid crystal polymer or an alignment liquid crystal layer fixed onto a supportive substrate that reflects either clockwise or counterclockwise circularly-polarized light while transmitting other light.
  • PCF350 trade name
  • Transmax trade name
  • the transmission light enters the polarizing plate by matching the polarization axis so that absorption loss due to the polarizing plate is controlled and the light can be transmitted efficiently.
  • the transmission circularly-polarized light is converted to linearly-polarized light before entering the polarizing plate in an aspect of controlling of the absorption loss, though the circularly-polarized light can enter the polarizer directly.
  • Circularly-polarized light can be converted to linearly-polarized light by using a quarter wavelength plate for a retardation plate.
  • a retardation plate having a function as a quarter wavelength plate in a wide wave range including a visible light region can be obtained, for example, by laminating a retardation layer functioning as a quarter wavelength plate for monochromatic light such as light having 550 nm wavelength and another retardation plate showing a separate optical retardation property (e.g., a retardation plate functioning as a half wavelength plate). Therefore, a retardation plate arranged between a polarizing plate and a brightness enhancement film can comprise a single layer or at least two layers of retardation layers.
  • a cholesteric liquid crystal layer also can be provided by combining layers different in the reflection wavelength and it can be configured by laminating two or at least three layers. As a result, the obtained retardation plate can reflect circularly-polarized light in a wide wavelength range including a visible light region, and this can provide transmission circularly-polarized light in a wide wavelength range.
  • any of the above-mentioned various polarizing plates according to the third example can be an optical film made by laminating the polarizing plate and two or at least three optical layers.
  • the polarizing plate can be a reflective polarizing plate or a semitransparent polarizing plate for elliptically-polarized light, which is prepared by combining either the above-mentioned reflective polarizing plate or a semitransparent polarizing plate with a retardation plate.
  • An optical film comprising a laminate of at least two optical layers can be formed in a method of laminating layers separately in a certain order for producing a liquid crystal display or the like. Since an optical film that has been laminated previously has excellent stability in quality and assembling operability, efficiency in producing a liquid crystal display can be improved. Any appropriate adhesion means such as a pressure-sensitive adhesive layer can be used for laminating the polarizing plate and optical layers.
  • the above-described layers composing the optical film of the present invention can have ultraviolet absorption power as a result of treatment with an ultraviolet absorber such as an ester salicylate compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex salt compound.
  • an ultraviolet absorber such as an ester salicylate compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, and a nickel complex salt compound.
  • a liquid crystal panel of the present invention includes at least one of the polarizer of the present invention and an optical film (hereinafter, referred to as ‘optical film’), which is arranged on at least one surface of the liquid crystal cell.
  • any of conventionally known liquid crystal cells can be used suitably without any particular limitations. Since the polarizer or the like of the present invention is useful for a liquid crystal display that allows polarized light to enter a liquid crystal cell so as to display, for example, liquid crystal cells using TN (twist nematic) liquid crystal or STN (supertwist nematic) liquid crystal are preferred.
  • TN twist nematic
  • STN supertwist nematic
  • liquid crystal cells of IPS In-Plane switching
  • VA Very Aligned
  • OCB Optically Compensated Birefringence
  • non-twist liquid crystal a guest-host base liquid crystal having a dichroic dye dispersed in a liquid crystal, a ferroelectric liquid crystal or the like are suitable as well.
  • a system for driving the liquid crystal there is no particular limitation about the system for driving the liquid crystal.
  • the optical films such as the polarizing plates can be arranged on only one of the surfaces of the liquid crystal cell, or they can be arranged on both the surfaces.
  • the optical films arranged on both the surfaces can be the same type or different from each other.
  • the polarizing plates or optical members on the surfaces can be the same or can be varied.
  • one or at least two layers of ordinary members such as a prism array sheet, a lens array sheet, and a light-diffusion plate can be arranged at proper positions.
  • FIGS. 3-5 show an example of a liquid crystal panel in which the optical film of the present invention is arranged. These figures show cross sections of a liquid crystal cell and an optical film in a laminated state, and they are hatched for distinguishing the components from each other. In the respective figures, common components are provided with same numbers.
  • the liquid crystal panel of the present invention will not be limited to the example.
  • the liquid crystal panel in FIG. 3 has a liquid crystal cell 12 and polarizing plates 11 , where the polarizing plates 11 are arranged respectively on both the surfaces of the liquid crystal cell 12 .
  • a liquid crystal is held between an array substrate and a filter substrate.
  • the liquid crystal panel in FIG. 4 has a liquid crystal cell 12 , polarizing plates 11 and retardation plates 13 , where the polarizing plates 11 are laminated on both the surfaces of the liquid crystal cell 12 via the retardation plates 13 .
  • the retardation plates 13 and the polarizing plates 11 can be arranged, as integrated optical films according to the present invention, on both the surfaces of the liquid crystal cell 12 .
  • the liquid crystal panel in FIG. 5 (A) includes a liquid crystal cell 12 , polarizing plates 11 and a polarization converter 14 , where the polarizing plates 11 are laminated respectively on both the surfaces of the liquid crystal cell 12 and the polarization converter 14 is further laminated on one surface of one of the polarizing plates.
  • Elements as mentioned above can be used for the polarization converter 14 , and the examples include a composite of a quarter wavelength plate 15 and a cholesteric liquid crystal 16 as shown in (B), and an anisotropic multilayer thin film reflective polarizer 17 as shown in (C).
  • the polarizing plates 11 and the polarization converter 14 can be arranged, as an integrated optical film according to the present invention, on one surface of the liquid crystal cell 12 .
  • a liquid crystal display of the present invention is a liquid crystal display including a liquid crystal panel, and the liquid crystal panel is of the present invention.
  • This liquid crystal display can include a light source further. Though there is no particular limitation for the light source, a flat light source that emits polarized light is preferred for example, since the light energy can be used effectively.
  • liquid crystal display it is also possible to further arrange a diffusion plate, an anti-glare layer, an anti-reflection film, a protective layer/plate, on an optical film (polarizing plate) at the viewing side.
  • a retardation plate or the like for compensation can be arranged appropriately between a liquid crystal cell and a polarizing plate in the liquid crystal panel.
  • an electroluminescent (EL) display of the present invention has at least one of the polarizer of the present invention and the optical film of the present invention.
  • This EL display can be an organic EL display or an inorganic EL display.
  • polarizer and the polarizing film of the present invention are useful particularly when any of linearly-polarized light, circularly-polarized light or elliptically-polarized light is emitted from the EL layer, or when obliquely emitted light is polarized partially even if natural light is emitted in the front direction.
  • an organic EL display has a luminant (organic EL luminant) that is prepared by laminating a transparent electrode, an organic luminant layer and a metal electrode in this order on a transparent substrate.
  • the organic luminant layer is a laminated body of various organic thin films.
  • Known examples thereof include a laminate of a hole injection layer made of triphenylamine derivative or the like and a luminant layer made of a fluorescent organic solid such as anthracene; a laminate of the ruminant layer and an electron injection layer made of perylene derivative or the like; or a laminate of the hole injection layer, the luminant layer and the electron injection layer.
  • the organic EL display emits light on the principle of a system of applying a voltage to the transparent electrode and the metal electrode so as to inject holes and electrons into the organic luminant layer, energy generated by the re-bonding of these holes and electrons excites the fluorescent material, and the excited fluorescent material emits light when it returns to the basis state.
  • the re-bonding mechanism of the holes and electrons is similar to that of an ordinary diode. Current and the light emitting intensity exhibit a considerable nonlinearity accompanied with a rectification with respect to the applied voltage.
  • the organic EL display it is preferred for the organic EL display that at least one of the electrodes is transparent so as to obtain luminescence at the organic ruminant layer.
  • a transparent electrode of a transparent conductive material such as indium tin oxide (ITO) is used for the anode.
  • ITO indium tin oxide
  • metal electrodes such as Mg—Ag, and Al—Li may be used.
  • the organic ruminant layer is made of a film that is extremely thin such as about 10 nm. Therefore, the organic luminant layer can transmit substantially whole light as the transparent electrode does. As a result, when the layer does not illuminate, a light beam entering from the surface of the transparent substrate and passing through the transparent electrode and the organic luminant layer before being reflected at the metal layer comes out again to the surface of the transparent substrate. Thereby, the display surface of the organic EL display looks like a mirror when viewed from the exterior.
  • the organic EL display according to the present invention includes, for example, the organic EL luminant formed by providing a transparent electrode on the surface of the organic ruminant layer and a metal electrode on the backside of the organic luminant layer, and preferably, an optical film (e.g., polarizing plate) according to the present invention is arranged on the surface of the transparent electrode. More preferably, a ⁇ /4 plate is arranged between the polarizing plate and an EL device. By arranging the polarizing film of the present invention, the organic EL display has an effect of suppressing external reflection and improving visibility. It is also preferable that an additional retardation plate is arranged between the transparent electrode and the polarizing film.
  • an optical film e.g., polarizing plate
  • the retardation plate and the optical film function to polarize light which enters from outside and is reflected by the metal electrode, and thus the polarization has an effect that the mirror of the metal electrode cannot be viewed from the exterior.
  • the mirror of the metal electrode can be blocked completely by forming the retardation plate with a quarter wavelength plate and adjusting an angle formed by the polarization direction of the retardation plate and the polarizing plate to be ⁇ /4. That is, the polarizing plate transmits only the linearly-polarized light constituent among the external light entering the organic EL display.
  • the linearly-polarized light is changed into elliptically-polarized light by the retardation plate.
  • the retardation plate is a quarter wavelength plate and when the angle of the polarization direction provided by the polarizing plate and the retardation plate is ⁇ /4, the light is changed into circularly-polarized light.
  • this circularly-polarized light passes through the transparent substrate, the transparent electrode, and the organic thin film. After being reflected by the metal electrode, the light passes again through the organic thin film, the transparent electrode and the transparent substrate, and turns into linearly-polarized light at the retardation plate. Moreover, since the linearly-polarized light crosses the polarization direction of the polarizing plate at a right angle, it cannot pass through the polarizing plate. As a result, the mirror of the metal electrode can be blocked completely.
  • An in-house production method for the liquid crystal display of the present invention and an EL display includes subjecting at least either the polarizer of the present invention or the optical film of the present invention to a chip-cut and immediately bonding it to the display device, where the polarizer of the present invention has a surface-protective film on the display side while having a pressure-sensitive adhesive layer and a peeling layer on the other side.
  • a prompt measurement is required for detecting a defective area, and also it is required to determine markings by setting a boundary sample or by an in-line measurement.
  • the production method of the present invention it is possible for the polarizer of the present invention or the optical film, that any parts not satisfying the above condition (1) is marked and punched out and then immediately bonded to a liquid crystal panel or to an EL display so as to produce various display devices.
  • the term ‘in-house’ denotes in general a collective line including punching of a polarizing plate in a roiled state, inspecting, and bonding to a LCD.
  • a polarizer was produced by subjecting a PVA film to a swelling treatment, a dying treatment, a crosslinking treatment, a stretching treatment and a washing treatment according to the conditions as indicated in the Table 1 below, and a polarizing plate was produced by using the polarizer. Then, performance of the polarizer and the polarizing plate was evaluated.
  • the PVA films used were a PVA film having a polarization degree of 2400 (a product of Kuraray Co., Ltd., with a trade name of VF-PS#7500, the width being 600 mm) and a PVA film having a polarization degree of 2600 (a product of the Nippon Synthetic Chemical Industry Co., Ltd., with a trade name of OPL M-7500, the width being 600 mm).
  • Types of the PVA films used in the respective Examples and Comparative Examples are shown depending on the polarization degrees in the Table 1 below.
  • the thickness and the thickness fluctuation of the PVA films (untreated films) are also shown in Table 1.
  • a PVA film was subjected to a swelling treatment under the condition as shown in Table 1 below. Specifically, the PVA film was impregnated in a water bath (swelling bath) and stretched. Table 1 indicates impregnation time, temperature of the swelling bath, and stretch rate with respect to an unswelled PVA film (untreated film). Here, a guide roll was used for improving the drainage in the swelling bath (hereinafter, the same).
  • the PVA film was pulled out of the swelling bath, impregnated in an aqueous solution (dyebath) containing 0.03 wt % of iodine, and further stretched. Impregnation time, temperature of the dyebath and a stretch rate with respect to the length of the untreated film are shown in Table 1 below.
  • the PVA film was pulled out of the dyebath, impregnated in an aqueous solution (crosslinking bath) containing boric acid and KI, and further stretched. Impregnation time, temperature of the crosslinking bath, a stretch rate with respect to the length of the untreated film, and concentrations of boric acid and KI in the crosslinking bath are shown in Table 1 below.
  • the PVA film was pulled out of the crosslinking bath, impregnated in an aqueous solution (stretching bath) containing boric acid and KI, and further stretched. Impregnation time, temperature of the stretching bath, a stretch rate with respect to the length of the untreated film, and concentrations of boric acid and KI in the stretching bath are indicated in Table 1 below. Time of impregnating in the stretching bath (time for the stretching treatment) is also indicated in Table 1.
  • the PVA film was pulled out of the stretching bath, impregnated in a KI aqueous solution (washing bath) and washed with water.
  • KI concentration in the washing bath and the temperature of the washing bath are indicated in Table 1 below.
  • a TAC film (trade name: KC4UVX2MW) produced by Konica Corp. was impregnated previously in a 40° C. aqueous solution containing 5 wt % NaOH for 2 minutes, washed in 30° C. pure water for 1 minute, and further dried at 100° C. for 2 minutes, so that a saponified protective film (thickness: 40 ⁇ m) was produced.
  • a retardation meter (trade name: KOBRA 21ADH produced by Oji Scientific Instruments)
  • the in-plane retardation was 1 nm
  • the thickness-direction retardation was 27 nm (measurement wavelength: 550 nm).
  • the protective films were bonded to both the surfaces of the polarizer by using a 3 wt % aqueous solution of PVA, and a drying treatment (65° C., 5 minutes) was carried out so as to produce a polarizing plate.
  • the in-plane retardation of the polarizing plate was measured (measurement wavelength: 1000 nm) by using KOBRA-31PR (trade name; produced by Oji Scientific Instruments). Specifically, measurement was carried out at 12276 points in total at a pitch of 2 mm within the plane of a polarizing plate 250 mm in length and 200 mm in width. The results are shown in Table 2, as a retardation fluctuation range of the polarizing plate.
  • Transmittance was measured by means of a spectral transmittance meter (trade name; DOT-3C produced by Murakami Color Research Laboratory), and denoted as a Y-value whose visibility was corrected in view of two-degrees-visual field (light source C) according to JIS Z8701.
  • a spectral transmittance meter trade name; DOT-3C produced by Murakami Color Research Laboratory
  • a Y-value whose visibility was corrected in view of two-degrees-visual field (light source C) according to JIS Z8701.
  • a polarization degree was obtained by calculating a measurement result of transmittance (H 0 and H 90 ) in accordance with the method for measuring transmittance, and by using the following formula.
  • H 0 denotes a transmittance obtained by laminating two polarizing films so that the polarizing axes become parallel
  • H 90 denotes a transmittance obtained by laminating two polarizing films so that the polarizing axes become perpendicular to each other.
  • the parallel transmittance (H 0 ) and the perpendicular transmittance (H 90 ) are Y values corrected in the visibility as mentioned above.
  • Polarization ⁇ ⁇ Degree ⁇ ( % ) H 0 - H 90 H 0 + H 90 ⁇ 100 (4) Measurement of Single Hue, Parallel Hue and Crossed Hue
  • a single hue ‘a’, a single hue ‘b’, a parallel hue ‘a’, a parallel hue ‘b’, a crossed hue ‘a’ and a crossed hue ‘b’ were measured by using an integrating-sphere spectral transmittance meter (trade name DOT-3C; manufactured by Murakami Color Research Laboratory). The results are shown in Table 2 below.
  • Each of the polarizing plates obtained in Examples and Comparative Examples was cut to a piece of 25 cm (length) ⁇ 20 cm (width), which was then bonded to a surface of a high-contrast type IPS liquid crystal cell (light source side) via a pressure-sensitive adhesive, while SEG1425DU (trade name, produced by Nitto Denko Corporation) was bonded to the other surface (visible side) of the liquid crystal cell.
  • the thus obtained liquid crystal panel was disposed on any of the backlights (A-D) described below, so that the (manufactured) polarizing plate of the liquid crystal panel at the light source side faces downwards.
  • the liquid crystal panel was observed in the front direction (0°) and in the oblique directions (30°, 60°) on the visible side, and irregularities at the time of black display was evaluated on the basis of the evaluation criteria mentioned below. The results are shown in Table 3 below.
  • FIG. 6 is a schematic cross-sectional view showing a backlight A.
  • this backlight 6 includes a wedge-shaped light-guiding plate 22 with a printed back face, to which a cold cathode ray tube 26 and a lamp house 27 were provided, and a diffusion plate 21 and a diffusion-reflection plate 23 are arranged respectively on the upper and lower surfaces thereof.
  • FIG. 7 is a schematic cross-sectional view of a backlight B.
  • this backlight 7 is made by arranging a laminate of a cholesteric layer and a ⁇ /4 plate, on the backlight 6 shown in FIG. 6 .
  • the laminate was arranged so that the cholesteric face ( 16 ) would face the backlight 6 while the ⁇ /4 plate ( 15 ) would face the visible side.
  • adjustment would be carried out for maximizing the quantity of transmitted light.
  • the laminate of the cholesteric layer and the ⁇ /4 plate was prepared by eliminating only the polarizing plate from PCF400TEG (trade name) produced by Nitto Denko Corporation.
  • FIG. 8 is a schematic cross-sectional view showing a backlight C. As shown in this figure, this backlight 8 is made by arranging an anisotropic multilayer thin film reflective polarizer 17 (trade name: DBEF, produced by 3M Co.) on the backlight 6 as shown in FIG. 6 . When arranging the liquid crystal cell on this backlight 8 as mentioned above, adjustment would be carried out for maximizing the quantity of transmitted light.
  • DBEF anisotropic multilayer thin film reflective polarizer
  • FIG. 9 (A) is a schematic cross-sectional view of a backlight D, and (B) is a schematic and partial view of (A).
  • this backlight 9 is formed by providing a cold cathode ray tube 26 and a lamp house 27 on a wedge-shaped light-guiding plate 25 formed with prisms on the light-emitting surface, and a diffusion-reflection plate 23 and prism sheet 24 were arranged on the lower and upper surfaces of the light-guiding plate 25 .
  • the prism sheet 24 was arranged so that its prism face would face the prism face of the light-guiding plate 25 .
  • a diffusion plate 21 was further arranged on the upper surface of the prism sheet 24 .
  • Example 2 1110-1150 ⁇ 3.2-3.9 9 cm 58 nm 44.0 99.98 ⁇ 1.3 3.6 ⁇ 2.2 6.4 0.4 ⁇ 2.6
  • Example 3 1110-1150 ⁇ 4.5-4.1 17 cm 49 nm 44.0 99.97 ⁇ 1.2 2.9 ⁇ 2.0 5.5 0.3 ⁇ 1.9
  • Example 4 1120-1190 ⁇ 4.1-3.9 7 cm 65 nm 43.9 99.96 ⁇ 1.1 2.9 ⁇ 2.1 5.3 0.3 ⁇ 2.0
  • Example 5 1190-1270 ⁇ 5.2-5.6 8 cm 62 nm 44.0 99.97 ⁇ 1.3 3.3 ⁇ 2.2 6.0 0.4 ⁇ 2.2
  • Example 6 1010-1080 ⁇ 4.3-4.9 9 cm 56 nm 44.0 99.97 ⁇ 1.4 3.4 ⁇ 2.1 6.2 0.3 ⁇ 2.3
  • Example 7 1060-1120 ⁇ 4.7-4.6 10 cm 43 nm 44.0 99.97 ⁇ 1.3 3.3 ⁇ 2.2 6.1
  • the polarizers of Comparative Examples As shown in Table 2, for the polarizers of Comparative Examples, the fluctuation ranges of the in-plane retardations at 1000 nm were out of the range of 950 to 1350 nm, and thus the evaluations of the display irregularities were inferior as shown in Table 3. On the contrary, the polarizing plates including the polarizers according to Examples and having fluctuations in a range of 950 to 1350 nm had excellent display characteristics as the display irregularities were suppressed. The results indicate that the polarizers of the present invention serve to provide various image display devices with suppressed display irregularities.
  • the polarizer of the present invention as an optical film such as a polarizing plate for a liquid crystal panel, a liquid crystal display or the like, display irregularities are prevented and excellent display characteristics can be achieved.
  • the polarizer and the polarizing plate or the like can be marked by an in-line measurement, for example, off-line processes such as visual inspection and packing immediately after the cutting of the polarizer can be omitted, and this can realize an in-house production in which the polarizers will be bonded collectively to liquid crystal displays or EL display devices. In this manner, for example, the cost for the display devices can be reduced and the management of the production process can be facilitated, resulting in improvement from the industrial viewpoint.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Polarising Elements (AREA)
  • Liquid Crystal (AREA)
  • Electroluminescent Light Sources (AREA)
US10/522,187 2002-07-24 2003-07-24 Polarizer, optical film using it, image display unit using them Abandoned US20060098137A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US12/230,372 US8698981B2 (en) 2002-07-24 2008-08-28 Polarizer, optical film using the same, and image display device using the same

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2002215855 2002-07-24
JP2002-215855 2002-07-24
PCT/JP2003/009367 WO2004019086A1 (ja) 2002-07-24 2003-07-24 偏光子、それを用いた光学フィルム、それらを用いた画像表示装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/230,372 Continuation US8698981B2 (en) 2002-07-24 2008-08-28 Polarizer, optical film using the same, and image display device using the same

Publications (1)

Publication Number Publication Date
US20060098137A1 true US20060098137A1 (en) 2006-05-11

Family

ID=31937790

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/522,187 Abandoned US20060098137A1 (en) 2002-07-24 2003-07-24 Polarizer, optical film using it, image display unit using them
US12/230,372 Expired - Fee Related US8698981B2 (en) 2002-07-24 2008-08-28 Polarizer, optical film using the same, and image display device using the same

Family Applications After (1)

Application Number Title Priority Date Filing Date
US12/230,372 Expired - Fee Related US8698981B2 (en) 2002-07-24 2008-08-28 Polarizer, optical film using the same, and image display device using the same

Country Status (6)

Country Link
US (2) US20060098137A1 (ja)
JP (1) JP2010152374A (ja)
KR (4) KR20090008452A (ja)
CN (2) CN1672069A (ja)
TW (1) TWI266907B (ja)
WO (1) WO2004019086A1 (ja)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050253494A1 (en) * 2004-05-17 2005-11-17 Lg Electronics Inc. Organic EL display
US20050259202A1 (en) * 2002-07-31 2005-11-24 Shinichi Takada Method for manufacturing surface protective film for transparent conductive film
US20050280358A1 (en) * 2004-06-17 2005-12-22 Yaw-Chung Cheng Light-polarizing film with high permeability for improving an interference light of a color organic light emitting diode
US20060227423A1 (en) * 2003-04-21 2006-10-12 Yuuji Saiki Polarizer, method for producing same, polarizing plate, optical film, and image display
US20060263609A1 (en) * 2005-05-18 2006-11-23 Hironori Yoshida Optical element and projection type image display apparatus having optical element therein
US20080171196A1 (en) * 2007-01-11 2008-07-17 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) Reflecting film excellent in cohesion resistance and sulfur resistance
US20080286455A1 (en) * 2006-02-24 2008-11-20 Nitto Denko Corporation Method for producing polarizer, polarizer, polarizing plate, optical film, image display, and cleaning apparatus
US20100033810A1 (en) * 2006-12-27 2010-02-11 Nitto Denko Corporation Polarizer protective film, polarizing plate, and image display apparatus
US20100047484A1 (en) * 2006-12-27 2010-02-25 Nitto Denko Corporation Polarizer protective film, polarizing plate, and image display apparatus
US20100053524A1 (en) * 2008-08-29 2010-03-04 Su Chang An Display device
US20100238379A1 (en) * 2009-03-23 2010-09-23 Nitto Denko Corporation Composite polarizing plate and liquid crystal display device
US20100314995A1 (en) * 2007-02-09 2010-12-16 Sumitomo Chemical Company, Limited Organic el element and method for manufacturing the organic el element and organic el element evaluating method
EP2211397A3 (en) * 2009-01-21 2014-06-25 Samsung Display Co., Ltd. Organic Light Emitting Diode Display
US20160200256A1 (en) * 2015-01-14 2016-07-14 Nitto Denko Corporation Image display mirror for a vehicle
US20160221508A1 (en) * 2015-02-02 2016-08-04 Nitto Denko Corporation Image display mirror for a vehicle
US20160377778A1 (en) * 2013-11-29 2016-12-29 Sumitomo Chemical Company, Limited Polarizer and polarizing plate including same
US20170031214A1 (en) * 2015-07-28 2017-02-02 Samsung Display Co. Ltd. Liquid crystal display device and method of manufacturing the same
US9696473B2 (en) 2013-10-31 2017-07-04 Lg Chem, Ltd. Laminate, method for preparing thin polarizer by using same, thin polarizer, and polarizing plate
US9709719B2 (en) 2013-11-29 2017-07-18 Sumitomo Chemical Company, Limited Polarizer and polarizing plate including same
US10942387B2 (en) * 2017-09-14 2021-03-09 Nitto Denko Corporation Optical laminate

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100544327B1 (ko) * 2005-08-02 2006-01-23 신화오플라주식회사 유기발광다이오드 디스플레이용 염료계 원편광판
GB2467691A (en) 2008-09-05 2010-08-11 Aueon Inc Methods for stratifying and annotating cancer drug treatment options
JP4928529B2 (ja) * 2008-11-12 2012-05-09 日東電工株式会社 偏光板の製造方法、偏光板、光学フィルムおよび画像表示装置
JP5503935B2 (ja) * 2009-09-30 2014-05-28 富士フイルム株式会社 ハードコートフィルム、反射防止フィルム、偏光板及び画像表示装置
EP2541306B1 (en) * 2010-02-24 2020-01-15 Mitsubishi Gas Chemical Company, Inc. Method for producing an aromatic polycarbonate polarising lens
EP3572528A1 (en) 2010-09-24 2019-11-27 The Board of Trustees of the Leland Stanford Junior University Direct capture, amplification and sequencing of target dna using immobilized primers
JP6121091B2 (ja) * 2011-08-09 2017-04-26 日東電工株式会社 偏光子及びその製造方法
WO2013023220A2 (en) 2011-08-11 2013-02-14 Life Technologies Corporation Systems and methods for nucleic acid-based identification
JP5815492B2 (ja) * 2011-11-01 2015-11-17 富士フイルム株式会社 光学フィルム、偏光板、画像表示装置及び３ｄ画像表示システム
TW201337349A (zh) * 2012-03-12 2013-09-16 Innocom Tech Shenzhen Co Ltd 光學構件及顯示系統
KR101628428B1 (ko) * 2012-12-17 2016-06-08 제일모직주식회사 편광판, 이의 제조방법 및 이를 포함하는 광학표시장치
JP6191197B2 (ja) * 2013-03-29 2017-09-06 住友化学株式会社 偏光フィルムの製造方法
KR101892333B1 (ko) * 2015-04-15 2018-08-27 삼성에스디아이 주식회사 광학 필름, 이를 포함하는 표시 장치 및 광학 필름의 제조방법
KR101694257B1 (ko) 2016-06-20 2017-01-10 에스케이씨 주식회사 편광자 보호 필름, 이를 포함하는 편광판, 및 이를 구비한 표시 장치
KR101694258B1 (ko) * 2016-06-20 2017-01-09 에스케이씨 주식회사 편광자 보호 필름, 이를 포함하는 편광판, 및 이를 구비한 표시 장치
CN106154381A (zh) * 2016-07-26 2016-11-23 上海理工大学 二维牛眼结构太赫兹cdma系统时域编码器和解码器
CN106443850A (zh) * 2016-09-20 2017-02-22 上海理工大学 一维超结构太赫兹cdma系统时域编码器和解码器
JP2018072712A (ja) * 2016-11-02 2018-05-10 日東電工株式会社 偏光板
CN106405701B (zh) * 2016-11-21 2018-12-14 上海理工大学 未达到精度要求的中阶梯光栅闪耀角再次精密加工方法
TWI631392B (zh) * 2017-05-23 2018-08-01 明基材料股份有限公司 背光模組
CN108983332A (zh) * 2018-07-27 2018-12-11 惠州市华星光电技术有限公司 具有吸光功能的偏光片、液晶显示面板和液晶显示器
KR20230060807A (ko) * 2021-10-28 2023-05-08 엘지디스플레이 주식회사 표시 장치

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4025688A (en) * 1974-08-01 1977-05-24 Polaroid Corporation Polarizer lamination
US5523863A (en) * 1988-10-19 1996-06-04 Fergason; James L. Controlled liquid crystal optical polarizer method and apparatus
US5875014A (en) * 1996-05-09 1999-02-23 Sumitomo Chemical Company, Limited Optically anisotropic film and liquid crystal display apparatus
US6049428A (en) * 1994-11-18 2000-04-11 Optiva, Inc. Dichroic light polarizers
US20010033349A1 (en) * 1999-12-09 2001-10-25 Masaru Honda Polarizer, polarizing light source device and liquid crystal display
US20010039319A1 (en) * 2000-05-02 2001-11-08 Kuraray Co., Ltd. Polyvinyl alcohol polymer film, method of producing the same and polarization film
US20020001700A1 (en) * 2000-05-12 2002-01-03 Kuraray Co., Ltd. Polyvinyl alcohol film and polarization film
US20020113922A1 (en) * 1999-09-20 2002-08-22 Seiichi Kusumoto Polarizing film polarizing plate and liquid crystal display
US20020145801A1 (en) * 2001-04-06 2002-10-10 Kazuki Tsuchimoto Manufacturing method of polarizing film, polarizing film, optical film, and visual display
US6606136B2 (en) * 2000-09-21 2003-08-12 Sumitomo Chemical Company, Limited Iodine-type polarizing plate enables neutral white in white display and neutral black in black display

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU4429489A (en) 1988-10-19 1990-05-14 James L. Fergason Variable density light control apparatus and method
JP3342516B2 (ja) * 1992-10-27 2002-11-11 株式会社クラレ Ｐｖａ系フィルム及び光学用フィルムの製造方法
JPH06347641A (ja) * 1993-06-07 1994-12-22 Kuraray Co Ltd 新規な偏光フィルム
JPH10268294A (ja) * 1997-03-28 1998-10-09 Canon Inc 液晶装置
US5970597A (en) 1998-05-13 1999-10-26 Eastman Kodak Company Precision assembly technique using alignment fixture and the resulting assembly
CN1161628C (zh) 1999-11-12 2004-08-11 钟渊化学工业株式会社 透明薄膜及其制造方法和包含该透明薄膜的椭圆形偏振片
JP2001228332A (ja) 1999-12-09 2001-08-24 Sumitomo Chem Co Ltd 偏光素子、偏光光源装置及び液晶表示装置
JP2001228333A (ja) * 1999-12-09 2001-08-24 Sumitomo Chem Co Ltd 半透過半反射性の光学素子及びそれを用いた光学装置
JP2001343529A (ja) 2000-03-30 2001-12-14 Kanegafuchi Chem Ind Co Ltd 偏光子保護フィルムおよびその製造方法
JP2001311826A (ja) * 2000-05-01 2001-11-09 Nitto Denko Corp 高輝度円偏光フィルムとこれを用いた表示装置及び有機エレクトロルミネッセンス表示装置
JP3514386B2 (ja) * 2000-05-02 2004-03-31 株式会社クラレ ポリビニルアルコール系重合体フィルムとその製造法
JP4646356B2 (ja) 2000-05-12 2011-03-09 株式会社クラレ ポリビニルアルコールフィルムの製造法
JP3422759B2 (ja) * 2000-07-17 2003-06-30 株式会社クラレ ポリビニルアルコール系重合体フィルムとその製造法および偏光フィルム
JP2002328233A (ja) 2001-05-02 2002-11-15 Kanegafuchi Chem Ind Co Ltd 透明フィルム
JP2002333522A (ja) * 2001-05-07 2002-11-22 Nitto Denko Corp 偏光フィルム、偏光板及びそれを用いた液晶表示装置
JP2003029040A (ja) * 2001-07-18 2003-01-29 Teijin Ltd 光学用フィルム、位相差フィルム及びそれらの製造方法
JP2003172822A (ja) * 2001-12-07 2003-06-20 Fuji Photo Film Co Ltd 偏光板、偏光板の製造方法および液晶表示装置
JP4975236B2 (ja) * 2002-07-24 2012-07-11 日東電工株式会社 偏光子、およびそれを用いた光学フィルム、ならびにそれらを用いた画像表示装置

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4025688A (en) * 1974-08-01 1977-05-24 Polaroid Corporation Polarizer lamination
US5523863A (en) * 1988-10-19 1996-06-04 Fergason; James L. Controlled liquid crystal optical polarizer method and apparatus
US6049428A (en) * 1994-11-18 2000-04-11 Optiva, Inc. Dichroic light polarizers
US5875014A (en) * 1996-05-09 1999-02-23 Sumitomo Chemical Company, Limited Optically anisotropic film and liquid crystal display apparatus
US20020113922A1 (en) * 1999-09-20 2002-08-22 Seiichi Kusumoto Polarizing film polarizing plate and liquid crystal display
US7006174B2 (en) * 1999-09-20 2006-02-28 Nitto Denko Corporation Polarizing film polarizing plate and liquid crystal display
US20010033349A1 (en) * 1999-12-09 2001-10-25 Masaru Honda Polarizer, polarizing light source device and liquid crystal display
US20010039319A1 (en) * 2000-05-02 2001-11-08 Kuraray Co., Ltd. Polyvinyl alcohol polymer film, method of producing the same and polarization film
US20020001700A1 (en) * 2000-05-12 2002-01-03 Kuraray Co., Ltd. Polyvinyl alcohol film and polarization film
US6606136B2 (en) * 2000-09-21 2003-08-12 Sumitomo Chemical Company, Limited Iodine-type polarizing plate enables neutral white in white display and neutral black in black display
US20020145801A1 (en) * 2001-04-06 2002-10-10 Kazuki Tsuchimoto Manufacturing method of polarizing film, polarizing film, optical film, and visual display

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050259202A1 (en) * 2002-07-31 2005-11-24 Shinichi Takada Method for manufacturing surface protective film for transparent conductive film
US7408604B2 (en) * 2002-07-31 2008-08-05 Nitto Denko Corporation Method for manufacturing surface protective film for transparent conductive film
US20100085641A1 (en) * 2003-04-21 2010-04-08 Nitto Denko Corporation Polarizer, method of manufacturing the same, polarizing plate, optical film, and image display
US20060227423A1 (en) * 2003-04-21 2006-10-12 Yuuji Saiki Polarizer, method for producing same, polarizing plate, optical film, and image display
US7651643B2 (en) * 2003-04-21 2010-01-26 Nitto Denko Corporation Polarizer, method for producing same, polarizing plate, optical film, and image display
EP1598878A3 (en) * 2004-05-17 2007-05-02 Lg Electronics Inc. Organic EL display
US7755262B2 (en) 2004-05-17 2010-07-13 Lg Display Co., Ltd. Organic EL display
US20050253494A1 (en) * 2004-05-17 2005-11-17 Lg Electronics Inc. Organic EL display
US20050280358A1 (en) * 2004-06-17 2005-12-22 Yaw-Chung Cheng Light-polarizing film with high permeability for improving an interference light of a color organic light emitting diode
US20060263609A1 (en) * 2005-05-18 2006-11-23 Hironori Yoshida Optical element and projection type image display apparatus having optical element therein
US20080286455A1 (en) * 2006-02-24 2008-11-20 Nitto Denko Corporation Method for producing polarizer, polarizer, polarizing plate, optical film, image display, and cleaning apparatus
US8303867B2 (en) 2006-02-24 2012-11-06 Nitto Denko Corporation Method for producing polarizer
US20100047484A1 (en) * 2006-12-27 2010-02-25 Nitto Denko Corporation Polarizer protective film, polarizing plate, and image display apparatus
US20100033810A1 (en) * 2006-12-27 2010-02-11 Nitto Denko Corporation Polarizer protective film, polarizing plate, and image display apparatus
US8367200B2 (en) * 2007-01-11 2013-02-05 Kobe Steel, Ltd. Reflecting film excellent in cohesion resistance and sulfur resistance
US20080171196A1 (en) * 2007-01-11 2008-07-17 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) Reflecting film excellent in cohesion resistance and sulfur resistance
US20100314995A1 (en) * 2007-02-09 2010-12-16 Sumitomo Chemical Company, Limited Organic el element and method for manufacturing the organic el element and organic el element evaluating method
US20100053524A1 (en) * 2008-08-29 2010-03-04 Su Chang An Display device
US7956959B2 (en) * 2008-08-29 2011-06-07 Lg Display Co., Ltd. Display device and method of manufacturing of the same
EP2211397A3 (en) * 2009-01-21 2014-06-25 Samsung Display Co., Ltd. Organic Light Emitting Diode Display
US20100238379A1 (en) * 2009-03-23 2010-09-23 Nitto Denko Corporation Composite polarizing plate and liquid crystal display device
US8390764B2 (en) * 2009-03-23 2013-03-05 Nitto Denko Corporartion Composite polarizing plate having a light diffusion pressure-sensitive adhesion layer and liquid crystal display device
US9696473B2 (en) 2013-10-31 2017-07-04 Lg Chem, Ltd. Laminate, method for preparing thin polarizer by using same, thin polarizer, and polarizing plate
US9709719B2 (en) 2013-11-29 2017-07-18 Sumitomo Chemical Company, Limited Polarizer and polarizing plate including same
US20160377778A1 (en) * 2013-11-29 2016-12-29 Sumitomo Chemical Company, Limited Polarizer and polarizing plate including same
US9703025B2 (en) * 2013-11-29 2017-07-11 Sumitomo Chemical Company, Limited Polarizer and polarizing plate including same
US20160200256A1 (en) * 2015-01-14 2016-07-14 Nitto Denko Corporation Image display mirror for a vehicle
US10377312B2 (en) * 2015-01-14 2019-08-13 Nitto Denko Corporation Image display mirror for a vehicle
US9616816B2 (en) * 2015-02-02 2017-04-11 Nitto Denko Corporation Image display mirror for a vehicle
US20160221508A1 (en) * 2015-02-02 2016-08-04 Nitto Denko Corporation Image display mirror for a vehicle
US20170031214A1 (en) * 2015-07-28 2017-02-02 Samsung Display Co. Ltd. Liquid crystal display device and method of manufacturing the same
US9910318B2 (en) * 2015-07-28 2018-03-06 Samsung Display Co., Ltd. Liquid crystal display device and method of manufacturing the same
US10234728B2 (en) 2015-07-28 2019-03-19 Samsung Display Co., Ltd. Liquid crystal display device and method of manufacturing the same
US10942387B2 (en) * 2017-09-14 2021-03-09 Nitto Denko Corporation Optical laminate

Also Published As

Publication number Publication date
KR20120070618A (ko) 2012-06-29
US20090002608A1 (en) 2009-01-01
US8698981B2 (en) 2014-04-15
KR101348469B1 (ko) 2014-01-07
KR20090008452A (ko) 2009-01-21
CN101900851A (zh) 2010-12-01
KR20050030210A (ko) 2005-03-29
JP2010152374A (ja) 2010-07-08
KR20090008453A (ko) 2009-01-21
TW200401909A (en) 2004-02-01
CN1672069A (zh) 2005-09-21
WO2004019086A1 (ja) 2004-03-04
TWI266907B (en) 2006-11-21

Similar Documents

Publication Publication Date Title
US8698981B2 (en) Polarizer, optical film using the same, and image display device using the same
USRE44315E1 (en) Polarizing film and image display
US7815972B2 (en) Method for manufacturing polarizing film and polarizing film and optical film manufactured by using the method
US7203002B2 (en) Polarizer, polarizing plate, liquid crystal display, and image display, and a method for producing the polarizer
US6859241B2 (en) Method of producing polarizing plate, and liquid crystal display comprising the polarizing plate
US7298443B2 (en) Optical compensating film, polarizing plate and a liquid crystal display using the same
WO2006054597A1 (ja) 光学補償層付偏光板、液晶パネル、液晶表示装置、画像表示装置および光学補償層付偏光板の製造方法
JP2003279748A (ja) 偏光フィルムおよび画像表示装置
US6831713B2 (en) Polarizing plate having all surfaces and sides covered with low moisture-permeable layers and liquid crystal display using the same
JP4136871B2 (ja) 光学フィルムおよび画像表示装置
US20020145690A1 (en) Semi-transmissible reflector, semi-transmission type polarizer and liquid-crystal display device using the sames
US20030197939A1 (en) Polarizing film and process for producing it, polarizing plate, and optical element
US7968143B2 (en) Method for manufacturing polarizing film, polarizing film obtained by the method, and image display apparatus using the polarizing film
JP4198559B2 (ja) 偏光フィルムの製造方法、およびそれを用いた偏光フィルムならびに光学フィルム
JP3938923B2 (ja) Ｉｐｓモード液晶表示装置
JP4975236B2 (ja) 偏光子、およびそれを用いた光学フィルム、ならびにそれらを用いた画像表示装置
US6847419B2 (en) Polarizing plate and liquid crystal display using the same
JP2004093993A (ja) 偏光子、それを用いた光学フィルム、およびそれを用いた液晶表示装置ならびにエレクトロルミネッセンス表示装置
JP2005266325A (ja) 偏光フィルムの製造方法、偏光フィルムおよびそれを用いた光学フィルムならびに画像表示装置
JP2003307625A (ja) 偏光子、偏光板、液晶表示装置および画像表示装置ならびに偏光子の製造方法
JP2002333523A (ja) 偏光板及びそれを用いた液晶表示装置
US20030086170A1 (en) Polarizing plate and a liquid crystal display using the same
JP2005266326A (ja) 偏光フィルムの製造方法、偏光フィルムおよびそれを用いた光学フィルムならびに画像表示装置
US20030152717A1 (en) Optical film and liquid crystal display using the same
JP4441283B2 (ja) 広視野角偏光板の製造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: NITTO DENKO CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAMEYAMA, TADAYUKI;MIZUSHIMA, HIROAKI;SUGINO, YOUICHIROU;AND OTHERS;REEL/FRAME:017007/0785

Effective date: 20050106

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION